Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
  • C08J5/241—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres
  • C08J5/243—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres using carbon fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/40—Shaping or impregnating by compression not applied
  • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
  • B29C70/44—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
  • B29C70/446—Moulding structures having an axis of symmetry or at least one channel, e.g. tubular structures, frames
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/003—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised by the matrix material, e.g. material composition or physical properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/40—Shaping or impregnating by compression not applied
  • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
  • B29C70/46—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs
  • B29C70/465—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs and impregnating by melting a solid material, e.g. sheets, powders of fibres
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
  • C08G59/22—Di-epoxy compounds
  • C08G59/24—Di-epoxy compounds carbocyclic
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/4007—Curing agents not provided for by the groups C08G59/42 - C08G59/66
  • C08G59/4014—Nitrogen containing compounds
  • C08G59/4021—Ureas; Thioureas; Guanidines; Dicyandiamides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/50—Amines
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
  • C08J5/0405—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres
  • C08J5/042—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres with carbon fibres
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
  • C08J5/249—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs characterised by the additives used in the prepolymer mixture
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
  • C08K5/0025—Crosslinking or vulcanising agents; including accelerators
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/16—Nitrogen-containing compounds
  • C08K5/21—Urea; Derivatives thereof, e.g. biuret
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2063/00—Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2307/00—Use of elements other than metals as reinforcement
  • B29K2307/04—Carbon
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2023/00—Tubular articles
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2463/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins

Definitions

• the present invention relates to a prepreg, a fiber-reinforced composite resin molded article, a method for producing a tubular molded article, an epoxy resin composition, and a tubular molded article.
• a fiber-reinforced composite resin molded article which is one of fiber-reinforced composite materials, is light-weight, has high strength, and has high rigidity, so that the fiber-reinforced composite resin molded article has been widely used from sports/leisure applications to industrial applications such as automobiles and aircraft.
• a fiber-reinforced composite resin tubular body has been widely used for sports/leisure applications such as fishing poles, golf club shafts, ski poles, and bicycle frames.
• the fiber-reinforced composite resin molded article As a method for producing the fiber-reinforced composite resin molded article, there is a method of using an intermediate material in which a reinforcing material made of long fibers such as reinforcing fibers is impregnated with a matrix resin, that is, using a prepreg. According to this method, there is an advantage that the content of the reinforcing fiber in the fiber-reinforced composite resin molded article can be easily controlled and the content thereof can be designed to be higher.
• Examples of a specific method for obtaining the fiber-reinforced composite resin molded article from the prepreg include a molding method using an autoclave, press molding, internal pressure molding, and oven molding. In any one of these methods, usually, in a case where two or more prepregs are laminated, molded into a desired shape, and then heat-cured, it takes approximately 2 to 6 hours to cure the laminate under the condition of approximately 160° C. or higher. That is, high temperature and long-term treatment are required for the production of the fiber-reinforced composite resin molded article.
• molding can be performed at a relatively low temperature of approximately 100° C. to 140° C. in a short time of approximately several minutes to several tens of minutes.
• the fiber-reinforced composite resin molded article in order to avoid deformation in a case of taking out the fiber-reinforced composite resin molded article from the mold, it is required for the fiber-reinforced composite resin molded article to have heat resistance. Specifically, it is desired that the glass transition temperature of the cured prepreg, that is, the fiber-reinforced composite resin molded article, is higher than the temperature of the mold during molding.
• an epoxy resin composition having excellent mechanical properties, heat resistance, and handleability has been widely used.
• it is required for epoxy resin compositions used for sports/leisure applications, industrial applications, and the like to have both breaking strain and heat resistance.
• it is effective to reduce the crosslink density of the epoxy resin composition.
• the crosslink density of the epoxy resin composition is reduced, the glass transition temperature of the cured product is lowered, and the heat resistance tends to be lowered.
• the glass transition temperature of a cured product of the epoxy resin composition is lowered, the glass transition temperature of the fiber-reinforced composite resin molded article is also lowered. Therefore, it is difficult to achieve both the breaking strain and the heat resistance of the fiber-reinforced composite resin molded article.
• an epoxy resin composition or a prepreg which can be cured in a short time even at a low temperature so as to enable to perform high-cycle molding and from which a fiber-reinforced composite resin molded article having excellent mechanical properties, especially excellent breaking strain and heat resistance, is obtained has been required.
• Patent Document 1 discloses a prepreg that an epoxy resin composition using, as a latent curing agent, dicyandiamide which has excellent breaking strain, and using, as a thermoplastic resin elastomer, polyvinyl formal is used as a matrix resin.
• the prepreg in which reinforcing fibers are impregnated into the epoxy resin composition, disclosed in Patent Document 1, requires a curing time of 2 hours at 130° C., and does not meet the above requirements.
• One of objects of the present invention is to provide a prepreg that can be cured in a short time even at a low temperature, and can obtain a fiber-reinforced composite resin molded article having excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance; and a fiber-reinforced composite resin molded article having excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance.
• the embodiment has the following aspects.
• a prepreg comprising:
• epoxy resin composition includes the following component (A), component (B), component (C), and component (D),
• a content of the component (A) is 40% to 70% by mass and a content of the component (B) is 15% to 40% by mass.
• a mass ratio of the content of the component (A) to the content of the component (B) (content of component (A)/content of component (B)) in the epoxy resin composition is 1.2 or more.
• component (B) has a structural unit derived from a structure represented by Formula (2).
• n an integer of 1 to 30
• the reinforcing fiber is a carbon fiber.
• component (D) is an amine curing agent.
• component (C) is phenyldimethylurea.
• a content of the component (C) is 1 to 10 parts by mass with respect to the total mass (100 parts by mass) of all epoxy resins included in the epoxy resin composition.
• a content of the component (D) is 2 to 15 parts by mass with respect to the total mass (100 parts by mass) of all epoxy resins included in the epoxy resin composition.
• a fiber-reinforced composite resin molded article which is a cured product of a laminate in which two or more prepregs according to any one of [1] to [8] are laminated.
• a method for producing a tubular molded article comprising:
• a tubular prepreg including a resin composition and a reinforcing fiber in a mold
• resin composition includes the following component (A),
• component (B), and component (D) are components (B), and component (D),
• component (B) a novolac epoxy resin
• tubular molded article has an annular curved portion
• the method for producing a tubular molded article further includes a step of annularly bending the tubular prepreg.
• An epoxy resin composition comprising:
• a glass transition point of the epoxy resin composition is 140° C. or higher
• a curing completion time in the following measuring method is 12 minutes or less
• the cured resin plate has a bending strength of 174 MPa or more, a flexural modulus of 3.6 GPa or more, and a breaking strain of 9% or more.
• a change in torque value (N ⁇ m) at a die temperature of 140° C. is measured to obtain a torque-time curve; a time until an inclination of a tangent line of the obtained torque-time curve becomes 1/30 of a maximum value after the inclination reaches the maximum is defined as the curing completion time.
• epoxy resin has a structural unit derived from a structure represented by Formula (2).
• n an integer of 1 to 30
• the epoxy resin includes a urea compound.
• a tubular molded article having a curved portion comprising:
• the resin composition includes the following component (A), component (B), and component (D),
• component (B) a novolac epoxy resin
• the prepreg of the embodiment can be cured in a short time even at a low temperature, and can obtain a fiber-reinforced composite resin molded article having excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance.
• the fiber-reinforced composite resin molded article of the embodiment has excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance.
• the prepreg of the embodiment comprises an epoxy resin composition and a reinforcing fiber.
• the epoxy resin composition includes the following component (A), component (B), component (C), and component (D). Further, the epoxy resin composition may include a component (optional component) other than the component (A), the component (B), the component (C), and the component (D).
• the component (A) is an oxazolidone epoxy resin.
• the oxazolidone epoxy resin is an epoxy resin having an oxazolidone ring structure.
• the epoxy resin composition includes the component (A), workability of the prepreg at normal temperature is improved. Further, heat resistance, breaking strain, and adhesiveness of the cured product of the epoxy resin composition (hereinafter, also referred to as a “resin cured product”) to the reinforcing fiber are improved, and a fiber-reinforced composite resin molded article having excellent heat resistance and breaking strain can be obtained.
• the “normal temperature” means 30° C.
• the oxazolidone ring structure is formed by an addition reaction of an isocyanate group and an epoxy group.
• a method for producing the oxazolidone epoxy resin is not particularly limited, and for example, the oxazolidone epoxy resin can be obtained in a substantially theoretical amount by reacting an isocyanate compound and an epoxy resin in the presence of a catalyst used for forming an oxazolidone ring. It is preferable that the isocyanate compound and the epoxy resin are reacted in an equivalent ratio (isocyanate compound:epoxy resin) in a range of 1:2 to 1:10. In a case where the equivalent ratio of the isocyanate compound and the epoxy resin is within the above-described range, the heat resistance and water resistance of the resin cured product tend to be better.
• the isocyanate compound used as a raw material for the component (A) is not particularly limited, but in order to incorporate the oxazolidone ring structure into the skeleton of the epoxy resin, an isocyanate compound having a plurality of isocyanate groups is preferable. Further, in order for the resin cured product to have high heat resistance, diisocyanate having a rigid structure is preferable.
• isocyanate compound examples include bifunctional isocyanate compounds such as methane diisocyanate, butane-1,1-diisocyanate, ethane-1,2-diisocyanate, butane-1,2-diisocyanate, trans-vinylene diisocyanate, propane-1,3-diisocyanate, butane-1,4-diisocyanate, 2-butene-1,4-diisocyanate, 2-methylbutene-1,4-diisocyanate, 2-methylbutane-1,4-diisocyanate, pentane-1,5-diisocyanate, 2,2-dimethylpentane-1,5-diisocyanate, hexane-1,6-diisocyanate, heptane-1,7-diisocyanate, octane-1,8-diisocyanate, nonane-1,9-diisocyanate, decane-1
• One kind of these isocyanate compounds may be used alone, or two or more kinds thereof may be used in combination.
• a bifunctional isocyanate compound or a trifunctional isocyanate compound is preferable, a bifunctional isocyanate compound is more preferable, and a bifunctional isocyanate compound having a skeleton selected from isophorone, benzene, toluene, diphenylmethane, naphthalene, norbornene polymethylene polyphenylene polyphenyl, and hexamethylene is still more preferable.
• epoxy resin used as a raw material for the component (A) various epoxy resins can be used, but in order to efficiently incorporate the oxazolidone ring structure into the skeleton of the epoxy resin, an epoxy resin having epoxy groups at both ends of the molecule is preferable.
• epoxy resins include epoxy resins derived from dihydric phenols such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol AD, tetramethyl bisphenol S, tetrabromo bisphenol A, and biphenyl; epoxy resins derived from tris(glycidyloxyphenyl)alkanes and the like, such as 1,1,1-tris(4-hydroxyphenyl)methane, 1,1,1-tris(4-hydroxyphenyl)ethane, and 4,4-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene] bisphenol; and epoxy resins derived from novolac such as phenol novolac, cresol novolac, and bisphenol A novolac.
• the epoxy resin is not limited thereto.
• One kind of these epoxy resins may be used alone, or two or more kinds thereof may be used in combination.
• the epoxy resin from the viewpoint that suppressing an excessive increase in the viscosity of the component (A), a bisphenol A epoxy resin, a bisphenol F epoxy resin, or a biphenyl epoxy resin is preferable.
• a toluene skeleton such as tolylene diisocyanate (for example, 1-methylbenzene-2,4-diisocyanate, 1-methylbenzene-2,5-diisocyanate, 1-methylbenzene-2,6-diisocyanate, and 1-methylbenzene-3,5-diisocyanate) and two molecules of bis
• Examples of a commercially available product of the component (A) include AER 4152, AER 4151, LSA 3301, and LSA 2102 (all trade names, manufactured by Asahi Kasei Corporation); ACR 1348 (trade name, manufactured by ADEKA CORPORATION); DER (registered trademark; the same applies hereinafter) 852 and 858 (both trade names, manufactured by Dow Chemical Japan); TSR-400 (trade name, manufactured by DIC CORPORATION); and YD-952 (trade name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.). All of these commercially available products are preferably used in the embodiment, but AER 4152 or TSR-400 is particularly preferable.
• One kind of the component (A) may be used alone, or two or more kinds thereof may be used in combination.
• the content of the component (A) is 40% by mass or more, preferably 41% by mass or more and more preferably 42% by mass or more. Further, with respect to the total mass (100% by mass) of all epoxy resins included in the epoxy resin composition, the content of the component (A) is 70% by mass or less, preferably 65% by mass or less, more preferably 60% by mass or less, and particularly preferably 55% by mass or less.
• the content of the component (A) is, for example, preferably 40% to 70% by mass, more preferably 40% to 65% by mass, still more preferably 41% to 60% by mass, and even more preferably 42% to 55% by mass.
• the content of the component (A) is the above-described lower limit value or more with respect to the total mass (100% by mass) of all epoxy resins included in the epoxy resin composition, the heat resistance of the resin cured product, the adhesiveness to carbon fiber, and the mechanical properties tend to be improved, and a fiber-reinforced composite resin molded article having both heat resistance and mechanical properties are obtained.
• the content of the component (A) is the above-described upper limit value or less with respect to the total mass (100% by mass) of all epoxy resins included in the epoxy resin composition, a prepreg having excellent tack and drape properties can be obtained, and a resin cured product having high breaking strain and having no voids tends to be obtained.
• the component (B) is a novolac epoxy resin.
• the epoxy resin composition includes the component (B), it is possible to maintain good heat resistance of the resin cured product. In addition, fast-curing property of the epoxy resin composition is improved, and a prepreg which is cured in a short time even at a low temperature is obtained.
• component (B) examples include a phenol novolac epoxy resin, and a cresol novolac epoxy resin.
• the component (B) has a structural unit derived from a structure represented by Formula (1), and from the viewpoint of heat resistance, it is more preferable that the component (B) has a structural unit derived from a structure represented by Formula (2).
• R represents a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group, and n represents an integer of 1 to 30
• Examples of the alkyl group in R of Formula (1) include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group, and a methyl group is preferable.
• Examples of the alkoxy group in R of Formula (1) include a methoxy group and an ethoxy group, and a methoxy group is preferable.
• Examples of the aryl group in R of Formula (1) include a phenyl group and a naphthyl group, and a phenyl group is preferable.
• n an integer of 1 to 30
• Examples of a commercially available product of the phenol novolac epoxy resin include jER (registered trademark; the same applies hereinafter) 152 and 154 (both trade names, manufactured by Mitsubishi Chemical Corporation); and EPICLON (registered trademark; the same applies hereinafter) N-740 and N-775 (both trade names, manufactured by DIC CORPORATION).
• cresol novolac epoxy resin examples include EPICLON N-660 and N-665 (both trade name, manufactured by DIC CORPORATION); EOCN-1020 and EOCN-102S (both trade names, manufactured by Nippon Kayaku Co., Ltd.); and YDCN-700 and YDCN-701 (both trade names, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).
• One kind of the component (B) may be used alone, or two or more kinds thereof may be used in combination.
• the content of the component (B) is 15% by mass or more, preferably 20% by mass or more. Further, with respect to the total mass (100% by mass) of all epoxy resins included in the epoxy resin composition, the content of the component (B) is 40% by mass or less, preferably 35% by mass or less and more preferably 30% by mass or less.
• the content of the component (B) is, for example, preferably 15% to 40% by mass, more preferably 15% to 35% by mass, still more preferably 20% to 35% by mass, and even more preferably 20% to 30% by mass.
• the content of the component (B) is the above-described lower limit value or more with respect to the total mass (100% by mass) of all epoxy resins included in the epoxy resin composition, the heat resistance of the resin cured product tends to be improved, and a fiber-reinforced composite resin molded article having excellent heat resistance is obtained.
• the fast-curing property of the epoxy resin composition is improved, and a prepreg which is cured in a short time even at a low temperature is obtained.
• the content of the component (B) is the above-described upper limit value or less with respect to the total mass (100% by mass) of all epoxy resins included in the epoxy resin composition
• the mechanical properties of the resin cured product tends to be improved, and a fiber-reinforced composite resin molded article having excellent mechanical properties is obtained.
• a resin cured product having high breaking strain and having no voids tends to be obtained. Further, it is possible to suppress an excessive increase in the viscosity of the epoxy resin composition, which facilitates the preparation of the epoxy resin composition.
• the mass ratio of the content of the component (A) to the content of the component (B) (content of component (A)/content of component (B)) in the epoxy resin composition is preferably 1.2 or more and more preferably 1.6 or more.
• the mass ratio of the content of the component (A) to the content of the component (B) (content of component (A)/content of component (B)) in the epoxy resin composition is preferably 5.0 or less and more preferably 4.0 or less.
• the component (C) is a urea compound.
• the epoxy resin composition includes the component (C)
• the fast-curing property of the epoxy resin composition is improved, and a prepreg which is cured in a short time even at a low temperature is obtained.
• deterioration of the mechanical properties including breaking strain of the resin cured product can be suppressed.
• urea compound examples include 3-phenyl-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, and 2,4-bis(3,3-dimethylureido)toluene.
• the urea compound is preferably phenyldimethylurea (PDMU).
• Examples of a commercially available product of the urea compound include OMICURE (registered trademark; the same applies hereinafter) 24 (manufactured by PTI JAPAN Corporation) as 2,4-bis(3,3′-dimethylureaide) toluene (TBDMU); OMICURE 94 (manufactured by PTI JAPAN Corporation) as phenyldimethylurea (PDMU); OMICURE 52 and OMICURE 54 (manufactured by PTI JAPAN Corporation) as 4,4′-methylenebis(phenyldimethylurea) (MDMU); and DCMU 99 (manufactured by Hodogaya Chemical Co., Ltd.) as 3-(3,4-dichlorophenyl)-1,1-dimethylurea.
• the content of the component (C) is preferably 1 to 10 parts by mass and more preferably 2 to 8 parts by mass.
• the content of the component (C) is the above-described lower limit value or more with respect to the total mass (100 parts by mass) of all epoxy resins included in the epoxy resin composition, a sufficient curing promoting function is obtained.
• the content of the component (C) is the above-described upper limit value or less with respect to the total mass (100 parts by mass) of all epoxy resins included in the epoxy resin composition, the storage stability of the epoxy resin composition is enhanced.
• the component (D) is a curing agent.
• an amine curing agent is preferable.
• the amine curing agent is a particulate thermoactive latent curing agent, and is enable to cure at a relatively low temperature by being combined with other components. Further, since the amine curing agent has excellent dispersibility, the curing reaction speed is increased.
• amine curing agent examples include aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone, aliphatic amines, imidazole derivatives, dicyandiamide, tetramethylguanidine, thiourea-added amines, and isomers and variants thereof.
• aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone
• aliphatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone
• imidazole derivatives imidazole derivatives
• dicyandiamide tetramethylguanidine
• thiourea-added amines thiourea-added amines
• One kind of these amine curing agents may be used alone, or two or more kinds thereof may be used in combination.
• Examples of a commercially available product of the component (D) include DICYANEX (registered trademark; the same applies hereinafter) 1400F (trade name, manufactured by EVONIK Japan); and jERCURE (registered trademark) DICY 7 and DICY 15 (both trade names, manufactured by Mitsubishi Chemical Corporation).
• the content of the component (D) is preferably 2 to 15 parts by mass and more preferably 5 to 9 parts by mass.
• the curing reaction proceeds sufficiently.
• the content of the component (D) is the above-described upper limit value or less with respect to the total mass (100 parts by mass) of all epoxy resins included in the epoxy resin composition, the storage stability of the epoxy resin composition is enhanced, and physical properties of the resin cured product can be maintained well.
• the mass ratio of the content of the component (C) to the content of the component (D) (content of component (C)/content of component (D)) in the epoxy resin composition is preferably 0.2 or more and more preferably 0.4 or more.
• the mass ratio of the content of the component (C) to the content of the component (D) (content of component (C)/content of component (D)) in the epoxy resin composition is preferably 1.0 or less and more preferably 0.8 or less.
• the optional component examples include an epoxy resin other than the component (A) and the component (B) (hereinafter, also referred to as an “other epoxy resins”), a thermoplastic resin, and an additive.
• epoxy resins examples include bifunctional epoxy resins such as a bisphenol A epoxy resin, a bisphenol F epoxy resin, and an epoxy resin modified from these epoxy resins; and trifunctional or higher functional epoxy resins such as a naphthalene epoxy resin, a glycidylamine epoxy resin, and an epoxy resin modified from these epoxy resins.
• bifunctional epoxy resins such as a bisphenol A epoxy resin, a bisphenol F epoxy resin, and an epoxy resin modified from these epoxy resins
• trifunctional or higher functional epoxy resins such as a naphthalene epoxy resin, a glycidylamine epoxy resin, and an epoxy resin modified from these epoxy resins.
• other epoxy resins are not limited thereto.
• One kind of these other epoxy resins may be used alone, or two or more kinds thereof may be used in combination.
• Examples of a commercially available product of the bifunctional epoxy resin include the following.
• Examples of a commercially available product of the bisphenol A epoxy resin include jER 825, 826, 827, 828, 834, and 1001 (all trade names, manufactured by Mitsubishi Chemical Corporation); EPICLON 850 (trade name, manufactured by DIC CORPORATION); Epotohto (registered trademark; the same applies hereinafter) YD-128 (trade name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.); DER 331 and 332 (both trade names, manufactured by Dow Chemical Japan); and Bakelite (registered trademark, the same applies hereinafter) EPR 154, EPR 162, EPR 172, EPR 173, and EPR 174 (all trade names, manufactured by Bakelite AG).
• Examples of a commercially available product of the bisphenol F epoxy resin include jER 806, 807, and 1750 (all trade names, manufactured by Mitsubishi Chemical Corporation); EPICLON 830 (trade name, manufactured by DIC CORPORATION); Epotohto YD-170 and YD-175 (both trade names, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.); Bakelite EPR 169 (trade name, manufactured by Bakelite AG); and GY 281, GY 282, and GY 285 (all trade names, manufactured by Huntsman International LLC.).
• Examples of a commercially available product of the trifunctional or higher functional epoxy resin include the following.
• Examples of a commercially available product of the naphthalene epoxy resin include HP-4032 and HP-4700 (all trade names, manufactured by DIC CORPORATION); and NC-7300 (trade name, manufactured by Nippon Kayaku Co., Ltd.).
• Examples of a commercially available product of the glycidylamine epoxy resin include jER 630 (trade name, manufactured by Mitsubishi Chemical Corporation), Araldite (registered trademark) MY 0500, MY 0510, and MY 0600 (all trade names, manufactured by Huntsman International LLC.).
• thermoplastic resin examples include polyamide, polyester, polycarbonate, polyether sulfone, polyphenylene ether, polyphenylene sulfide, polyether ether ketone, polyether ketone, polyether imide, polyimide, polytetrafluoroethylene, polyether, polyolefin, liquid crystal polymer, polyarylate, polysulfone, polyacrylonitrile styrene, polystyrene, polyacrylonitrile, polymethylmethacrylate, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-ethylene-propylene-diene-styrene copolymer (AES resin), acrylonitrile-styrene-alkyl(meth) acrylate copolymer (ASA resin), polyvinyl chloride, polyvinyl formal, phenoxy resin, and block polymer.
• the thermoplastic resin is not limited thereto.
• thermoplastic resins may be used alone, or two or more kinds thereof may be used in combination.
• thermoplastic resins from the viewpoint of excellent resin flow controllability and the like, phenoxy resin, polyether sulfone, polyether imide, polyvinyl formal, or block polymer is preferable.
• the heat resistance and flame retardancy of the resin cured product are further enhanced.
• the tack of the obtained prepreg can be easily controlled within an appropriate range without impairing the heat resistance of the resin cured product.
• the adhesiveness between the reinforcing fiber and the resin cured product is further enhanced.
• the toughness and impact resistance of the resin cured product are improved.
• Examples of a commercially available product of the phenoxy resin include YP-50, YP-50S, YP70, ZX-1356-2, and FX-316 (all trade names, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).
• the commercially available product of the phenoxy resin is not limited thereto.
• Examples of a commercially available product of the polyvinyl formal include VINYLEC (registered trademark) K (average molecular weight: 59,000), L (average molecular weight: 66,000), H (average molecular weight: 73,000), and E (average molecular weight: 126,000) (all trade names, manufactured by JNC Corporation).
• the commercially available product of the polyvinyl formal is not limited thereto.
• polyether sulfone or polyether imide is preferably used as the thermoplastic resin.
• Examples of a commercially available product of the polyether sulfone include SUMIKAEXCEL (registered trademark) 3600P (average molecular weight: 16,400), 5003P (average molecular weight: 30,000), 5200P (average molecular weight: 35,000), and 7600P (average molecular weight: 45,300) (all trade names, manufactured by Sumitomo Chemical Company).
• Examples of a commercially available product of the polyether imide include ULTEM (registered trademark) 1000 (average molecular weight: 32,000), 1010 (average molecular weight: 32,000), and 1040 (average molecular weight: 20,000) (all trade names, manufactured by SABIC Innovative Plastics Japan).
• the commercially available product of the polyether imide is not limited thereto.
• Examples of a commercially available product of the block polymer include Nanostrength (registered trademark) M52, M52N, M22, M22N, 123, 250, 012, E20, and E40 (all trade names, manufactured by Arkema); and TPAE-8, TPAE-10, TPAE-12, TPAE-23, TPAE-31, TPAE-38, TPAE-63, TPAE-100, and PA-260 (all trade names, manufactured by T&K TOKA Corporation).
• the commercially available product of the block polymer is not limited thereto.
• the additive examples include a curing accelerator of the epoxy resin, an inorganic filler, an internal mold release agent, an organic pigment, and an inorganic pigment.
• the epoxy resin composition can be obtained, for example, by mixing the above-described components.
• Examples of a method for mixing each component include a method using a mixer such as a three-roll mill, a planetary mixer, a kneader, a homogenizer, and a homodisper.
• a mixer such as a three-roll mill, a planetary mixer, a kneader, a homogenizer, and a homodisper.
• the epoxy resin composition can be used for producing a prepreg by being impregnated into an aggregate of reinforcing fibers, for example, as described later.
• a film of the epoxy resin composition can be obtained by applying the epoxy resin composition to a release paper or the like and curing the epoxy resin composition.
• the epoxy resin composition obtained as described above can be cured in a short time even at a low temperature. Specifically, the complete curing time of the epoxy resin composition tends to be 12 minutes or less.
• the viscosity of the epoxy resin composition at 30° C. tends to be 100 to 1,000,000 Pa ⁇ s, and the tack adjustment and workability of the prepreg surface are excellent.
• the cured product (resin cured product) of the epoxy resin composition is excellent in mechanical properties such as flexural modulus, bending strength and breaking strain, and excellent in heat resistance.
• the flexural modulus of the cured product of the epoxy resin composition obtained by curing at 140° C. for 30 minutes tends to be 3.6 GPa or more
• the bending strength thereof tends to be 174 MPa or more
• the breaking strain thereof tends to be 9% or more.
• the glass transition temperature which is an index of the heat resistance of the cured product of the epoxy resin composition obtained under the same conditions, tends to be 140° C. or higher.
• low temperature means a temperature of 100° C. to 140° C.
• short time means 10 to 30 minutes.
• the reinforcing fiber exists as a reinforcing fiber base material (aggregate of reinforcing fibers) in the prepreg, and is preferably in a form of a sheet.
• the reinforcing fiber may be those in which the reinforcing fibers are arranged in a single direction, or may be those in which the reinforcing fibers are arranged in a random direction.
• the reinforcing fiber examples include a woven fabric of reinforcing fibers, a non-woven fabric of reinforcing fibers, and a sheet in which long fibers of reinforcing fibers are aligned in one direction.
• the reinforcing fiber is preferably a sheet formed of a bundle of reinforcing fibers in which long fibers are aligned in a single direction, and from the viewpoint of easy handling, the reinforcing fiber is preferably a woven fabric of reinforcing fibers.
• Examples of a material of the reinforcing fiber include glass fiber, carbon fiber (including graphite fiber), aramid fiber, and boron fiber.
• the reinforcing fiber is preferably a reinforcing fiber base material including carbon fiber.
• the fiber diameter of the carbon fiber is preferably 3 to 12 ⁇ m.
• the fiber diameter of the carbon fiber is the above-described lower limit value or more
• the carbon fibers are less likely to be cut or fluffed, in a case where the carbon fibers move laterally and rub against each other, or a case where the carbon fibers and the roll surface or the like rub against each other. Therefore, a fiber-reinforced composite material having stable strength can be suitably produced.
• the carbon fiber can be produced by a normal method.
• the number of carbon fibers in the carbon fiber bundle is preferably 1,000 to 70,000.
• the strand tensile strength of the carbon fiber is preferably 1.5 to 9 GPa, and the strand tensile elastic modulus of the carbon fiber is preferably 150 to 260 GPa.
• the strand tensile strength and strand tensile elastic modulus of the carbon fiber are values measured in accordance with JIS R 7601:1986.
• the prepreg can be obtained, for example, by impregnating an aggregate of reinforcing fibers with the above-described epoxy resin composition.
• the prepreg obtained as described above is an aggregate of reinforcing fibers impregnated with the epoxy resin composition.
• Examples of a method of impregnating the aggregate of reinforcing fibers with the epoxy resin composition include a wet method in which the epoxy resin composition is dissolved in a solvent such as methyl ethyl ketone and methanol to reduce the viscosity thereof, and then impregnated into an aggregate of reinforcing fibers; and a hot melt method (dry method) in which the epoxy resin composition is heated to reduce the viscosity thereof, and then impregnated into an aggregate of reinforcing fibers.
• the method of impregnating the aggregate of reinforcing fibers with the epoxy resin composition is not limited thereto.
• the wet method is a method in which an aggregate of reinforcing fibers is immersed in a solution of the epoxy resin composition and pulled up, and the solvent is evaporated using an oven or the like.
• the hot melt method a method of directly impregnating an aggregate of reinforcing fibers with the epoxy resin composition that the viscosity has been reduced by heating, or a method in which the epoxy resin composition is once applied to a surface of a base material such as release paper to produce a film, the films are laminated from both sides or one side of an aggregate of reinforcing fibers, and then a resin is impregnated into the aggregate of reinforcing fibers by heating and pressurizing is used.
• the coating layer obtained by coating on the surface of the base material such as release paper may be used in the hot melt method as being uncured, or may be used in the hot melt method after the coating layer is cured.
• the content of the epoxy resin composition in the prepreg (hereinafter, also referred to as a “resin content”) is preferably 15% to 50% by mass, more preferably 20% to 45% by mass, and still more preferably 25% to 40% by mass.
• the resin content is the above-described lower limit value or more, sufficient adhesiveness between the reinforcing fiber and the epoxy resin composition can be ensured. In a case where the resin content is the above-described upper limit value or less, the mechanical properties of the fiber-reinforced composite resin molded article are further enhanced.
• the prepreg of the embodiment described above includes the above-described epoxy resin composition and reinforcing fiber.
• the epoxy resin composition included in the prepreg of the embodiment can prevent a decrease in glass transition temperature and a decrease in curing rate.
• the prepreg of the embodiment can be cured in a short time even at a low temperature, and can obtain a fiber-reinforced composite resin molded article having excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance.
• the processing time can be shortened in the molding of the fiber-reinforced composite resin molded article, so that the fiber-reinforced composite resin molded article can be produced at low cost.
• the prepreg of the embodiment since the epoxy resin composition included in the prepreg of the embodiment has a controlled viscosity at 30° C., the prepreg of the embodiment is excellent in adjusting the tack on the surface of the prepreg and in workability.
• the fiber-reinforced composite resin molded article of the embodiment is a cured product of a laminate in which two or more prepregs of the embodiment described above are laminated. That is, the fiber-reinforced composite resin molded article of the embodiment includes a cured product of the epoxy resin composition included in the prepreg, and reinforcing fibers.
• the fiber-reinforced composite resin molded article can be obtained, for example, by a method in which two or more prepregs of the embodiment are laminated, and then the epoxy resin composition is heat-cured while applying pressure to the obtained laminate.
• Examples of a method of molding the fiber-reinforced composite resin molded article of the embodiment include a press molding method, an autoclave molding method, a bagging molding method, a wrapping tape method, an internal pressure molding method, a sheet wrap molding method, and resin transfer molding (RTM), vacuum assisted resin transfer molding (VaRTM; vacuum resin impregnation producing method), filament winding, or resin film infusion (RFI), in which an epoxy resin composition is impregnated into a filament or preform of reinforcing fibers and cured to obtain a molded product.
• the method of molding the fiber-reinforced composite resin molded article of the embodiment is not limited to these molding methods.
• the wrapping tape method is a method of molding a tubular fiber-reinforced composite resin molded article (fiber-reinforced composite resin tubular body) by winding the prepreg around a core metal such as a mandrel, and is preferably used in a case of producing a rod-shaped body such as a golf shaft and a fishing rod.
• the wrapping tape method is a method in which the prepreg is wound around the mandrel, a wrapping tape formed of a thermoplastic film is wrapped around the outside of the prepreg so as to fix the prepreg apply pressure to the prepreg, and after the epoxy resin composition in the prepreg is heat-cured in an oven, the core metal is removed, thereby obtaining a fiber-reinforced composite resin tubular body.
• the internal pressure molding method is a method that a preform in which the prepreg is wound around an internal pressure applying body such as a tube formed of a thermoplastic resin is set in a mold, and then a high-pressure gas is introduced into the internal pressure applying body to apply pressure, and at the same time, the mold is heated, thereby molding the fiber-reinforced composite resin molded article.
• the heating temperature is not particularly limited, but the molding time can be shorter as the temperature is higher, which is preferable. Specifically, the heating temperature is preferably 120° C. or higher and more preferably 140° C. or higher.
• the fiber-reinforced composite resin molded article of the embodiment described above is a cured product of a laminate in which two or more prepregs of the embodiment are laminated
• the fiber-reinforced composite resin molded article of the embodiment has excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance.
• the fiber-reinforced composite resin molded article of the embodiment is suitably used for sports applications, general industrial applications, and aerospace applications. More specifically, in sports applications, the fiber-reinforced composite resin molded article of the embodiment is suitably used for golf shafts, fishing rods, rackets for tennis and badminton, sticks for hockey and the like, and ski poles. Furthermore, in general industrial applications, the fiber-reinforced composite resin molded article of the embodiment is suitably used for structural materials of moving bodies such as automobiles, ships, and railroad vehicles, drive shafts, leaf springs, wind turbine blades, pressure vessels, flywheels, paper rollers, roofing materials, cables, and repair reinforcing materials.
• moving bodies such as automobiles, ships, and railroad vehicles, drive shafts, leaf springs, wind turbine blades, pressure vessels, flywheels, paper rollers, roofing materials, cables, and repair reinforcing materials.
• the epoxy resin composition in another embodiment which is different from the epoxy resin composition used in the prepreg of the embodiment described above, will be described below.
• the epoxy resin composition of the embodiment comprises an epoxy resin and a curing agent.
• Examples of the epoxy resin included in the epoxy resin composition of the embodiment include the above-described component (A), the above-described component (B), and other epoxy resins exemplified above as an optional component.
• the epoxy resin included in the epoxy resin composition of the embodiment preferably includes the component (A) or the component (B) described above, and more preferably includes the component (A) and component (B) described above.
• the specific components, contents, preferred aspects, and the like of the component (A) and the component (B) in the epoxy resin composition of the embodiment are as described above.
• the epoxy resin included in the epoxy resin composition of the embodiment preferably has a ring structure, and from the viewpoint of heat resistance, it is preferable to have a naphthalene structure, a dicyclopentadiene structure, or a structural unit derived from a structure represented by Formula (2).
• n an integer of 1 to 30
• Examples of the curing agent included in the epoxy resin composition of the embodiment include the above-described component (D).
• the specific components, contents, preferred aspects, and the like of the component (D) in the epoxy resin composition of the embodiment are as described above.
• the epoxy resin composition of the embodiment may include a urea compound.
• the urea compound include the above-described component (C).
• the specific components, contents, preferred aspects, and the like of the component (C) in the epoxy resin composition of the embodiment are as described above.
• the glass transition temperature which is an index of the heat resistance of the cured product of the epoxy resin composition, is generally 120° C. or higher, preferably 130° C. or higher, more preferably 135° C. or higher, and still more preferably 140° C. or higher. Further, from the viewpoint of toughness, the glass transition temperature is preferably 250° C. or lower, more preferably 200° C. or lower, and still more preferably 180° C. or lower.
• the curing completion time in the following measuring method is 12 minutes or less, preferably 11 minutes or less and more preferably 8 minutes or less.
• a change in torque value (N ⁇ m) at a die temperature of 140° C. is measured to obtain a torque-time curve.
• a time until an inclination of a tangent line of the obtained torque-time curve becomes 1/30 of the maximum value after the inclination reaches the maximum is defined as the curing completion time.
• the bending strength of the cured resin plate obtained by heating the epoxy resin composition at 130° C. to 150° C. is 174 MPa or more, preferably 175 MPa or more and more preferably 180 MPa or more, and from the viewpoint of cost, is preferably 250 MPa or less;
• the flexural modulus thereof is 3.6 GPa or more, preferably 3.7 GPa or more and more preferably 3.8 GPa or more, and from the viewpoint of cost, is preferably 5.0 MPa or less;
• the breaking strain thereof is 9% or more, preferably 9.5% or more and more preferably 10% or more, and from the viewpoint of cost, is preferably 20% or less.
• the epoxy resin composition of the embodiment can be cured in a short time even at a low temperature, and can obtain a resin molded article having excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance. Therefore, the epoxy resin composition of the embodiment is useful as a matrix resin used for prepreg.
• the method for producing a tubular molded article of the embodiment comprises the following steps.
• the tubular prepreg can be obtained by, for example, winding a prepreg including a resin composition and a reinforcing fiber around an internal pressure applying body such as a tube formed of a thermoplastic resin.
• the obtained tubular prepreg is set in the mold and heated 130° C. or higher, preferably 140° C. or higher, to be molded.
• the molding can be performed by inflating the internal pressure applying body by introducing a high-pressure gas, and pressing the tubular prepreg against the mold from the inside of the tubular prepreg.
• the resin composition included in the tubular prepreg used in the method for producing a tubular molded article of the embodiment includes the above-described component (A), component (B), and component (D).
• component (A), component (B), and component (D) The specific components, contents, preferred aspects, and the like of the component (A), the component (B), and the component (D) in the method for producing a tubular molded article of the embodiment are as described above.
• the resin composition included in the tubular prepreg used in the method for producing a tubular molded article of the embodiment may include a urea compound.
• the urea compound include the above-described component (C).
• the specific components, contents, preferred aspects, and the like of the component (C) in the method for producing a tubular molded article of the embodiment are as described above.
• the resin composition included in the tubular prepreg used in the method for producing a tubular molded article of the embodiment may be the above-described epoxy resin composition of the embodiment, or may be the epoxy resin composition included in the above-described prepreg of the embodiment.
• the method for producing a tubular molded article of the embodiment in a case where the tubular molded article has an annular curved portion, may further include a step of annularly bending the tubular prepreg.
• tubular molded article has an annular curved portion refers to applications such as a racket for tennis or badminton.
• the tubular molded article of the embodiment has a curved portion, preferably an annular curved portion, and includes a cured product of a resin composition and carbon fiber.
• the resin composition included the tubular molded article of the embodiment includes the above-described component (A), component (B), and component (D).
• the specific components, contents, preferred aspects, and the like of the component (A), the component (B), and the component (D) in the method for producing a tubular molded article of the embodiment are as described above. That is, the resin composition included in the tubular molded article of the embodiment may have the same specific components, contents, preferred aspects, and the like as those in the resin composition included in the tubular prepreg used in the method for producing a tubular molded article of the embodiment.
• An epoxy resin composition was prepared as follows according to formulations shown in Tables 1 to 3.
• components other than the component (C) and the component (D) were weighed in a glass flask, heated and mixed at 100° C. to obtain a uniform epoxy resin main agent.
• the obtained epoxy resin main agent is cooled to 60° C., the component (C) and the component (D) are weighed and added thereto, and an epoxy resin composition was obtained by being uniformly dispersed by heating and mixing the mixture at 60° C.
• the obtained epoxy resin composition was cast by sandwiching the obtained epoxy resin composition with glass plates together with a 2 mm-thick Teflon (registered trademark; the same applies hereinafter) spacer, and heat-cured at 140° C. for 30 minutes, thereby obtaining a cured resin plate (cured product of the epoxy resin composition) having a thickness of 2 mm.
• the obtained cured resin plate was measured and evaluated as follows.
• An epoxy resin composition was prepared as follows according to formulations shown in Table 3.
• components other than the component (C) and the component (D) were weighed in a glass flask, heated and mixed at 100° C. to obtain a uniform epoxy resin main agent.
• the obtained epoxy resin main agent is cooled to 60° C., the component (C) and the component (D) are weighed and added thereto, and an epoxy resin composition was obtained by being uniformly dispersed by heating and mixing the mixture at 60° C.
• the obtained epoxy resin composition was cast by sandwiching the obtained epoxy resin composition with glass plates together with a 2 mm-thick Teflon spacer, and heat-cured at 70° C. for 10 minutes and at 140° C. for 40 minutes, thereby obtaining a cured resin plate (cured product of the epoxy resin composition) having a thickness of 2 mm.
• the obtained cured resin plate was measured and evaluated as follows.
• a change in torque value (N ⁇ m) at a die temperature of 140° C. is measured under the measurement conditions shown below to obtain a torque-time curve.
• a time until an inclination of a tangent line of the obtained torque-time curve becomes 1/30 of the maximum value after the inclination reaches the maximum is defined as the curing completion time.
• the cured resin plate in each example was processed into a test piece having a length of 60 mm and a width of 8 mm.
• the obtained test piece was subjected to a three-point bending test under the following measurement conditions, thereby measuring the bending strength, flexural modulus, and breaking strain of the cured resin plate.
• the cured resin plate in each example was processed into a test piece having a length of 55 mm and a width of 12.5 mm.
• the storage elastic modulus (G′) was measured under the measurement conditions shown below, log G′ was plotted against temperature, and the temperature at an intersection of an approximate straight line of flat area of log G′ and an approximate straight line of area where G was transferred was recorded as the glass transition temperature (G′-Tg).
• All of the epoxy resin compositions obtained in Examples 1 to 4 had a curing completion time of 12 minutes or less. Further, the cured resin plate, which is a cured product of these epoxy resin compositions, had a bending strength of 174 MPa or more, a flexural modulus of 3.6 GPa or more, and a breaking strain of 9% or more, and the mechanical properties thereof were excellent. Further, the glass transition temperature of the cured resin plate was 140° C. or higher, and the heat resistance thereof was also excellent.
• the prepregs including the epoxy resin compositions obtained in Examples 1 to 4 could be cured in a short time even at a low temperature, and could obtain a fiber-reinforced composite resin molded article having excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance.
• the epoxy resin composition of Comparative Example 2 which did not include the component (B), had a long curing completion time. Further, the cured product of the epoxy resin composition had a low glass transition temperature and was inferior in heat resistance.
• the epoxy resin composition of Comparative Example 9 which did not include the component (C), had low bending strength, flexural modulus, and breaking strain, and was inferior in mechanical properties.
• the prepreg of the embodiment it is possible to be cured in a short time even at a low temperature, and to obtain a fiber-reinforced composite resin molded article having excellent mechanical properties such as flexural modulus, bending strength, and breaking strain, and excellent heat resistance. Therefore, according to the embodiment, it is possible to provide a wide range of molded bodies having high productivity, high efficiency, and excellent mechanical properties, for example, molded bodies for sports/leisure applications such as shafts for golf clubs, and molded bodies for industrial applications such as aircraft.

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• 2019
  • 2019-10-17 JP JP2020553296A patent/JP7524764B2/ja active Active
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